Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 The airborne research platform of the FU Berlin: Overview of measurements taken during the BBC campaign and presentation of first products and analysis Marc Schröder, Thomas Ruhtz, Eyk Bösche, Jürgen Fischer Institut für Weltraumwissenschaften Freie Universität Berlin Germany

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Table of contents Overview of measurements Calibration BBC casi data catalog casi cloudmask Statistical characterisation of clouds

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Overview of measurements Instrument casi FUBISS classic HDRAD FUBISS extended HMR, G12 MIDAC Description Compact airborne spectrographic imager, nadir radiances (vis) FUB integrated spectrographic sys- tem (radiances): 1 nadir,1 zenith (vis), 1nadir (highvis), 1 nadir (NIR) Radiometer from the University of Heidelberg, 4 visible channels Irradiances (vis), nadir, zenith Flight attitude (20 Hz), GPS (10 Hz) Fourierspectrometer (5-17  m) Status ok ok, except for NIR ok no HMR since , GPS ok no Amount 54 G 2 G 9 M 4 G 0.5 G 1 G

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Calibration examplary results for FUBISS vis nadir absolute calibrationspectral calibration

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Calibration: Spectral comparison Hintergrund Radiative smoothing (Bounded) cascade models Multifraktalität data taken from the leg04 time: utctime: utc

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Calibration: Time series comparison data taken from the leg04 wavelength: 753 nm

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 BBC casi data catalog Hintergrund Radiative smoothing (Bounded) cascade models Multifraktalität

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 BBC casi data catalog: Track overview start time stop time section length leg01 leg02 leg03 leg04 09:30:48 10:31:17 10km length: 28.69km / sections: 2 length: 30.22km / sections: 3 length: 29.27km / sections: 2 length: 57.11km / sections: 5 Date: Leg: 02

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 BBC casi data catalog: Images 34.2° altitude swath top of image correspondes to geograhpic north casi

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 casi cloudmask: Algorithm development casi nadir radiances, one received over cloud, the other over meadow, normalised to the respective radiance at 780 nm define ratio: r = L(490 nm) / L(780 nm) find thresholds: cloud if r  r T and cloud if L(490 nm)  L T (490 nm)

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 casi cloudmask development: Thresholds histograms of casi nadir radiances at 490 nm and the ratio r, data from , leg5 thresholds: r T = 0.5 and L T (490 nm) = 60 Wm -2 sr -1  m -1

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 casi cloudmask development: Cloud shadow on clouds white: cloudmask with previous condition only 2nd condition: r T  1.35 and L T (490 nm)  35 Wm -2 sr -1  m -1 gray: advanced cloudmas- king technique pm, leg2

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 casi cloudmask: Results I data from pm, leg6

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 casi cloudmask: Results II data from , leg7

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 casi cloudmask: Results III data from , leg1

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Power spectra Definition: Scale invariance: stationarity if stationary incre- ments if E(k) ~ |F(k)| 2 E(k) ~ k -   < 1 1 <  < m  =2.52  =1.37 data from , leg3 cloud fraction b = 0.97

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Structure function analysis 1)  (r;x) =  (x+r) -  (x) =  i+r -  i with i=1,...,N-r and N=L/l 2) ~ (r/L)  (q) with q  0 Results for H(q) =  (q) / q small scales r: H(q=1) = 0.47 large scales r: H(q=1) = 0.22

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 small scales r: C(q=1) = 0.11 large scales r: C(q=1) = 0.07 Singulare measures 1)  (1;x) =  (x+1) -  (x) =  i+1 -  i with i=1,2,...,N-1 and N=L/l 2)  (1;x) = |  (1;x)| / with = 1/(N-1)  |  (1;x)| 3)  (r;x) = 1/r   (r;x) 4) ~ (r/L) -K(q) with q  0 Results for C(q) = K(q) / (q-1) and C(q=1) = K´(q) | q=1

Marc Schröder et al., FUB BBC Workshop, Leipzig, 05.´02 Summary calibrated level 1b data for casi and FUBISS highvis, shortly available: FUBISS vis (nadir, zenith) delivered level 0b data to the IUP BBC casi data catalog, available for each day casi cloudmask, partly processed statistical characterisation of clouds: to be completed for days with high cloud fraction